标签：注释 back end reads 读取 循环列表 -- daemon 背景
模块：threading
#!/usr/bin/env python
#-*- coding: utf8 -*-
import sys
import time
import string
import threading
import datetime
fileinfo = sys.argv[1]
# 读取文件内容放入列表
host_list = []
port_list = []
# 定义函数：读取文件内容放入列表中
def CreateList():
f = file(fileinfo,‘r‘)
for line in f.readlines():
host_list.append(line.split(‘ ‘)[0])
port_list.append(line.split(‘ ‘)[1])
return host_list
return port_list
f.close()
# 单线程 循环函数，注释掉了
#def CreateInfo():
# for i in range(0,len(host_list)): # 单线程：直接循环列表
# time.sleep(1)
# TimeMark = datetime.datetime.now().strftime(‘%Y-%m-%d %H:%M:%S‘)
# print "The Server‘s HostName is %-15s and Port is %-4d !!! [%s]" % (host_list[i],int(port_list[i]),TimeMark)
#
# 定义多线程循环调用函数
def MainRange(start,stop): #提供列表index起始位置参数
for i in range(start,stop):
time.sleep(1)
TimeMark = datetime.datetime.now().strftime(‘%Y-%m-%d %H:%M:%S‘)
print "The Server‘s HostName is %-15s and Port is %-4d !!! [%s]" % (host_list[i],int(port_list[i]),TimeMark)
# 执行函数，生成列表
CreateList()
# 列表分割成：两部分 mid为列表的index中间位置
mid = int(len(host_list)/2)
# 多线程部分
threads = []
t1 = threading.Thread(target=MainRange,args=(0,mid))
threads.append(t1)
t2 = threading.Thread(target=MainRange,args=(mid,len(host_list)))
threads.append(t2)
for t in threads:
t.setDaemon(True)
t.start()
t.join()
print "ok"
----------------------------------------------------------------------
[root@monitor2 logdb]# ./Threadfor.py hostinfo.txt
The Server‘s HostName is 192.168.10.11 and Port is 1011 !!! [2017-01-10 14:51:51]
The Server‘s HostName is 192.168.10.18 and Port is 1018 !!! [2017-01-10 14:51:51]
The Server‘s HostName is 192.168.10.12 and Port is 1012 !!! [2017-01-10 14:51:52]
The Server‘s HostName is 192.168.10.19 and Port is 1019 !!! [2017-01-10 14:51:52]
The Server‘s HostName is 192.168.10.13 and Port is 1013 !!! [2017-01-10 14:51:53]
The Server‘s HostName is 192.168.10.20 and Port is 1020 !!! [2017-01-10 14:51:53]
The Server‘s HostName is 192.168.10.14 and Port is 1014 !!! [2017-01-10 14:51:54]
The Server‘s HostName is 192.168.10.21 and Port is 1021 !!! [2017-01-10 14:51:54]
The Server‘s HostName is 192.168.10.15 and Port is 1015 !!! [2017-01-10 14:51:55]
The Server‘s HostName is 192.168.10.22 and Port is 1022 !!! [2017-01-10 14:51:55]
The Server‘s HostName is 192.168.10.16 and Port is 1016 !!! [2017-01-10 14:51:56]
The Server‘s HostName is 192.168.10.23 and Port is 1023 !!! [2017-01-10 14:51:56]
The Server‘s HostName is 192.168.10.17 and Port is 1017 !!! [2017-01-10 14:51:57]
The Server‘s HostName is 192.168.10.24 and Port is 1024 !!! [2017-01-10 14:51:57]
The Server‘s HostName is 192.168.10.25 and Port is 1025 !!! [2017-01-10 14:51:58]
==================================以上部分完结===正确=========
=====经过调试出现新的问题======================================
第二部分：延伸问题
总结：以上运行结果没有问题！！！（但是调整参数：start，stop之后有问题：MainRange(start,stop)）
首先说明下两个概念问题：
join()：
1.方法的位置是在for循环外的，也就是说必须等待for循环里的两个进程都结束后，才去执行主进程（主进程指：本脚本中的print “OK”）。
2.可以理解成：t.join() 的t线程执行完之后，再继续执行后面的！！！（本脚本中的t.join()，是指t2线程）
可参考：
for i in range(0,4):
pass
print i
结果输出：3. 也就是for循环的最后一个i. 放在本脚本里，就是for循环的最后一个线程t2。然后t2完成之后，就是：print “OK”
setDaemon(True):
1.将线程声明为守护线程，必须在start() 方法调用之前设置，如果不设置为守护线程程序会被无限挂起。
2.换句话说：开启，子线程不会挂起，主线程执行了，子线程及时没执行完也会中断：比如本脚本里如果：t1>t2
===========解析=============================================================
重新编写输出文件内容：
[root@monitor2 logdb]# cat hostinfo.txt
192.168.10.00 0
192.168.10.01 1
192.168.10.02 2
192.168.10.03 3
192.168.10.04 4
192.168.10.05 5
192.168.10.06 6
192.168.10.07 7
192.168.10.08 8
192.168.10.09 9
192.168.10.10 10
192.168.10.11 11
192.168.10.12 12
192.168.10.13 13
192.168.10.14 14
原文脚本中：
for t in threads: t.setDaemon(True) t.start() t.join() print "ok"
分类解析：
基于原文脚本：
1. 以上基于线程执行次数：t1 <= t2 运行结果：正确
[root@monitor2 logdb]# ./Threadfor.py hostinfo.txt
The Server‘s HostName is 192.168.10.00 and Port is 00 !!! [2017-01-10 19:08:44],
The Server‘s HostName is 192.168.10.07 and Port is 07 !!! [2017-01-10 19:08:44],
The Server‘s HostName is 192.168.10.01 and Port is 01 !!! [2017-01-10 19:08:45],
The Server‘s HostName is 192.168.10.08 and Port is 08 !!! [2017-01-10 19:08:45],
The Server‘s HostName is 192.168.10.02 and Port is 02 !!! [2017-01-10 19:08:46],
The Server‘s HostName is 192.168.10.09 and Port is 09 !!! [2017-01-10 19:08:46],
The Server‘s HostName is 192.168.10.03 and Port is 03 !!! [2017-01-10 19:08:47],
The Server‘s HostName is 192.168.10.10 and Port is 10 !!! [2017-01-10 19:08:47],
The Server‘s HostName is 192.168.10.04 and Port is 04 !!! [2017-01-10 19:08:48],
The Server‘s HostName is 192.168.10.11 and Port is 11 !!! [2017-01-10 19:08:48],
The Server‘s HostName is 192.168.10.05 and Port is 05 !!! [2017-01-10 19:08:49],
The Server‘s HostName is 192.168.10.12 and Port is 12 !!! [2017-01-10 19:08:49],
The Server‘s HostName is 192.168.10.06 and Port is 06 !!! [2017-01-10 19:08:50],
The Server‘s HostName is 192.168.10.13 and Port is 13 !!! [2017-01-10 19:08:50],
The Server‘s HostName is 192.168.10.14 and Port is 14 !!! [2017-01-10 19:08:51],
ok
解析：开启setDaemon(True)，t1,t2同时依次执行，[t1,t2],[t1,t2],[t1,t2],[t1,t2],[t1,t2] . . . . . .[t1,t2], 下次循环t1结束，t2再执行一次，[,t2]，再下次，t2结束。t.join()==t2.join() 完成任务，继续执行主进程print “ok”
2.基于脚本中线程次数t1>t2，运行结果：错误
[root@monitor2 logdb]# ./Threadfor.py hostinfo.txt
t1: (0~13)
t2: (7~15)
The Server‘s HostName is 192.168.10.00 and Port is 00 !!! [2017-01-10 19:18:58],
The Server‘s HostName is 192.168.10.07 and Port is 07 !!! [2017-01-10 19:18:58],
The Server‘s HostName is 192.168.10.01 and Port is 01 !!! [2017-01-10 19:18:59],
The Server‘s HostName is 192.168.10.08 and Port is 08 !!! [2017-01-10 19:18:59],
The Server‘s HostName is 192.168.10.02 and Port is 02 !!! [2017-01-10 19:19:00],
The Server‘s HostName is 192.168.10.09 and Port is 09 !!! [2017-01-10 19:19:00],
The Server‘s HostName is 192.168.10.03 and Port is 03 !!! [2017-01-10 19:19:01],
The Server‘s HostName is 192.168.10.10 and Port is 10 !!! [2017-01-10 19:19:01],
The Server‘s HostName is 192.168.10.04 and Port is 04 !!! [2017-01-10 19:19:02],
The Server‘s HostName is 192.168.10.11 and Port is 11 !!! [2017-01-10 19:19:02],
The Server‘s HostName is 192.168.10.12 and Port is 12 !!! [2017-01-10 19:19:03],
The Server‘s HostName is 192.168.10.05 and Port is 05 !!! [2017-01-10 19:19:03],
The Server‘s HostName is 192.168.10.13 and Port is 13 !!! [2017-01-10 19:19:04],
The Server‘s HostName is 192.168.10.06 and Port is 06 !!! [2017-01-10 19:19:04],
The Server‘s HostName is 192.168.10.07 and Port is 07 !!! [2017-01-10 19:19:05],
The Server‘s HostName is 192.168.10.14 and Port is 14 !!! [2017-01-10 19:19:05],
ok
解析：t1,t2同时依次执行，t1>t2，当t2执行最后一次时，t.join()===t2.join()，t.join()完成任务，执行主程序print "ok"，由于：开启setDaemon(True)，t1,t2均不会被挂起，主程序结束，子程序即使没有执行完，也结束。如上述结果。
t2执行8次结束，t1也执行8次循环结束。
开启：t.setDaemon(True)：不会挂起，顺序执行
1.脚本如下：
for t in threads:
t.setDaemon(True)
t.start()
t.join() #在for循环里面
print "ok"
[root@monitor2 logdb]# ./Threadfor.py hostinfo.txt
t1: (0~13)
t2: (7~15)
The Server‘s HostName is 192.168.10.00 and Port is 00 !!! [2017-01-10 19:30:56]
The Server‘s HostName is 192.168.10.01 and Port is 01 !!! [2017-01-10 19:30:57]
The Server‘s HostName is 192.168.10.02 and Port is 02 !!! [2017-01-10 19:30:58]
The Server‘s HostName is 192.168.10.03 and Port is 03 !!! [2017-01-10 19:30:59]
The Server‘s HostName is 192.168.10.04 and Port is 04 !!! [2017-01-10 19:31:00]
The Server‘s HostName is 192.168.10.05 and Port is 05 !!! [2017-01-10 19:31:01]
The Server‘s HostName is 192.168.10.06 and Port is 06 !!! [2017-01-10 19:31:02]
The Server‘s HostName is 192.168.10.07 and Port is 07 !!! [2017-01-10 19:31:03]
The Server‘s HostName is 192.168.10.08 and Port is 08 !!! [2017-01-10 19:31:04]
The Server‘s HostName is 192.168.10.09 and Port is 09 !!! [2017-01-10 19:31:05]
The Server‘s HostName is 192.168.10.10 and Port is 10 !!! [2017-01-10 19:31:06]
The Server‘s HostName is 192.168.10.11 and Port is 11 !!! [2017-01-10 19:31:07]
The Server‘s HostName is 192.168.10.12 and Port is 12 !!! [2017-01-10 19:31:08]
The Server‘s HostName is 192.168.10.07 and Port is 07 !!! [2017-01-10 19:31:09]
The Server‘s HostName is 192.168.10.08 and Port is 08 !!! [2017-01-10 19:31:10]
The Server‘s HostName is 192.168.10.09 and Port is 09 !!! [2017-01-10 19:31:11]
The Server‘s HostName is 192.168.10.10 and Port is 10 !!! [2017-01-10 19:31:12]
The Server‘s HostName is 192.168.10.11 and Port is 11 !!! [2017-01-10 19:31:13]
The Server‘s HostName is 192.168.10.12 and Port is 12 !!! [2017-01-10 19:31:14]
The Server‘s HostName is 192.168.10.13 and Port is 13 !!! [2017-01-10 19:31:15]
The Server‘s HostName is 192.168.10.14 and Port is 14 !!! [2017-01-10 19:31:16]
ok
：解析：t.join()在for循环里面，t1.join()等待t1执行13次循环完毕;然后才执行t2,t2.join()等待t2循环执行8次；然后执行主线程print"ok"
:如上述结果：t1先执行完，再执行t2
：t1,t2大小无所谓，多线程没有效果
关闭：t.setDaemon(True) :线程会挂起
1.脚本如下：
for t in threads:
# t.setDaemon(True)
t.start()
t.join() #在for循环里面
print "ok"
[root@monitor2 logdb]# ./Threadfor.py hostinfo.txt
t1: (0~13)
t2: (7~15)
The Server‘s HostName is 192.168.10.00 and Port is 00 !!! [2017-01-10 19:37:11]
The Server‘s HostName is 192.168.10.01 and Port is 01 !!! [2017-01-10 19:37:12]
The Server‘s HostName is 192.168.10.02 and Port is 02 !!! [2017-01-10 19:37:13]
The Server‘s HostName is 192.168.10.03 and Port is 03 !!! [2017-01-10 19:37:14]
The Server‘s HostName is 192.168.10.04 and Port is 04 !!! [2017-01-10 19:37:15]
The Server‘s HostName is 192.168.10.05 and Port is 05 !!! [2017-01-10 19:37:16]
The Server‘s HostName is 192.168.10.06 and Port is 06 !!! [2017-01-10 19:37:17]
The Server‘s HostName is 192.168.10.07 and Port is 07 !!! [2017-01-10 19:37:18]
The Server‘s HostName is 192.168.10.08 and Port is 08 !!! [2017-01-10 19:37:19]
The Server‘s HostName is 192.168.10.09 and Port is 09 !!! [2017-01-10 19:37:20]
The Server‘s HostName is 192.168.10.10 and Port is 10 !!! [2017-01-10 19:37:21]
The Server‘s HostName is 192.168.10.11 and Port is 11 !!! [2017-01-10 19:37:22]
The Server‘s HostName is 192.168.10.12 and Port is 12 !!! [2017-01-10 19:37:23]
The Server‘s HostName is 192.168.10.07 and Port is 07 !!! [2017-01-10 19:37:24]
The Server‘s HostName is 192.168.10.08 and Port is 08 !!! [2017-01-10 19:37:25]
The Server‘s HostName is 192.168.10.09 and Port is 09 !!! [2017-01-10 19:37:26]
The Server‘s HostName is 192.168.10.10 and Port is 10 !!! [2017-01-10 19:37:27]
The Server‘s HostName is 192.168.10.11 and Port is 11 !!! [2017-01-10 19:37:28]
The Server‘s HostName is 192.168.10.12 and Port is 12 !!! [2017-01-10 19:37:29]
The Server‘s HostName is 192.168.10.13 and Port is 13 !!! [2017-01-10 19:37:30]
The Server‘s HostName is 192.168.10.14 and Port is 14 !!! [2017-01-10 19:37:31]
ok
解析：由于t.join()在循环里面，所以：t1线程执行完，才执行t2.是顺序执行的
t1,t2大小无所谓，多线程没有效果
2.脚本如下：
for t in threads:
# t.setDaemon(True)
t.start()
t.join() #在for循环外面
print "ok"
[root@monitor2 logdb]# ./Threadfor.py hostinfo.txt
t1: (0~13)
t2: (7~15)
The Server‘s HostName is 192.168.10.00 and Port is 00 !!! [2017-01-10 19:40:31]
The Server‘s HostName is 192.168.10.07 and Port is 07 !!! [2017-01-10 19:40:31]
The Server‘s HostName is 192.168.10.01 and Port is 01 !!! [2017-01-10 19:40:32]
The Server‘s HostName is 192.168.10.08 and Port is 08 !!! [2017-01-10 19:40:32]
The Server‘s HostName is 192.168.10.02 and Port is 02 !!! [2017-01-10 19:40:33]
The Server‘s HostName is 192.168.10.09 and Port is 09 !!! [2017-01-10 19:40:33]
The Server‘s HostName is 192.168.10.03 and Port is 03 !!! [2017-01-10 19:40:34]
The Server‘s HostName is 192.168.10.10 and Port is 10 !!! [2017-01-10 19:40:34]
The Server‘s HostName is 192.168.10.04 and Port is 04 !!! [2017-01-10 19:40:35]
The Server‘s HostName is 192.168.10.11 and Port is 11 !!! [2017-01-10 19:40:35]
The Server‘s HostName is 192.168.10.05 and Port is 05 !!! [2017-01-10 19:40:36]
The Server‘s HostName is 192.168.10.12 and Port is 12 !!! [2017-01-10 19:40:36]
The Server‘s HostName is 192.168.10.06 and Port is 06 !!! [2017-01-10 19:40:37]
The Server‘s HostName is 192.168.10.13 and Port is 13 !!! [2017-01-10 19:40:37]
The Server‘s HostName is 192.168.10.07 and Port is 07 !!! [2017-01-10 19:40:38]
The Server‘s HostName is 192.168.10.14 and Port is 14 !!! [2017-01-10 19:40:38]
ok
The Server‘s HostName is 192.168.10.08 and Port is 08 !!! [2017-01-10 19:40:39]
The Server‘s HostName is 192.168.10.09 and Port is 09 !!! [2017-01-10 19:40:40]
The Server‘s HostName is 192.168.10.10 and Port is 10 !!! [2017-01-10 19:40:41]
The Server‘s HostName is 192.168.10.11 and Port is 11 !!! [2017-01-10 19:40:42]
The Server‘s HostName is 192.168.10.12 and Port is 12 !!! [2017-01-10 19:40:43]
解析：t.join()在循环外面t.join()==t2.join(),
过程：t1>t2. 开始：同时执行。当t2执行8次循环完毕，t1也执行了8次。此时t2完毕，t.join()生效，会执行主进程print "ok". 主进程完毕。
由于，关闭：t.setDaemon(True)，未执行完毕的t1先前被挂起，接下来会继续，直到结束。如上述结果
t1<t2 就不会出现这种情况了。多线程是有效的。但是主线程的输出位置，错误！！
！
=============解决方法================================
解决方式：
1.只有两个线程时
修改原脚本：临时解决t1>t2
for t in threads:
t.setDaemon(True)
t.start()
threads[0].join() #指定t1,结束
print "ok"
解析：通过threads[0] 指定t1.join() ，等t1完成了，才执行主程序
2.多个线程时 也适用
for t in threads:
t.start()
for t in threads:
t.join()
print "ok"
解析：多个线程都等待，等所有都完成之后。才执行主线程print "ok"
3.事例：3个线程
[root@monitor2 logdb]# ./Threadfor.py hostinfo.txt
t1: (0~4) 循环4次
t2: (4~11) 循环7次
t3: (11~15) 循环4次
The Server‘s HostName is 192.168.10.00 and Port is 00 !!! [2017-01-10 20:07:31]
The Server‘s HostName is 192.168.10.04 and Port is 04 !!! [2017-01-10 20:07:31]
The Server‘s HostName is 192.168.10.11 and Port is 11 !!! [2017-01-10 20:07:31] 1次
The Server‘s HostName is 192.168.10.01 and Port is 01 !!! [2017-01-10 20:07:32]
The Server‘s HostName is 192.168.10.05 and Port is 05 !!! [2017-01-10 20:07:32]
The Server‘s HostName is 192.168.10.12 and Port is 12 !!! [2017-01-10 20:07:32] 2次
The Server‘s HostName is 192.168.10.02 and Port is 02 !!! [2017-01-10 20:07:33]
The Server‘s HostName is 192.168.10.06 and Port is 06 !!! [2017-01-10 20:07:33]
The Server‘s HostName is 192.168.10.13 and Port is 13 !!! [2017-01-10 20:07:33] 3次
The Server‘s HostName is 192.168.10.03 and Port is 03 !!! [2017-01-10 20:07:34]
The Server‘s HostName is 192.168.10.07 and Port is 07 !!! [2017-01-10 20:07:34]
The Server‘s HostName is 192.168.10.14 and Port is 14 !!! [2017-01-10 20:07:34] 4次
The Server‘s HostName is 192.168.10.08 and Port is 08 !!! [2017-01-10 20:07:35] 5次
The Server‘s HostName is 192.168.10.09 and Port is 09 !!! [2017-01-10 20:07:36] 6次
The Server‘s HostName is 192.168.10.10 and Port is 10 !!! [2017-01-10 20:07:37] 7次
ok
标签：注释 back end reads 读取 循环列表 -- daemon 背景
原文地址：http://www.cnblogs.com/cuisi/p/6275053.html
